Aurigny is rescheduling some flights between mid April and June and will levy a £2 fuel surcharge per sector.
The state-owned airline has seen a drop in demand until June and, as a result, is making some schedule changes.
People with bookings are being proactively emailed by Customer Services with the altered flight times.
As an example, the teatime Gatwick to Guernsey flight at the end of the May Bank Holiday has been brought forward by half an hour.
Philip Saunders, Chief Commercial Officer at Aurigny, says the impact of the Iran attacks is being felt locally just three weeks after the first missiles were fired:
“While a small island community, we are not immune from the realities presented by the global travel ecosystem.
"Current global events are impacting consumer confidence and changing travel behaviours."
He says bookings for May are around 13% down on last year.
Fuel represents around a third of Aurigny's costs, and because of the volatility of the price of crude, it is levying a £4 return trip surcharge. It says this is in common with other carriers.
The airline is amalgamating its flights to the south west, with a single aircraft serving both Bristol and Exeter.
Some flights to London City will temporarily go, but the airline will still fly there six times a week.
Mr Saunders says the Wednesday Paris service is being suspended until peak summer:
“Although, there is some softening of demand for near-term travel, we are pleased to be observing strength from July onwards, as we welcome more UK holidaymakers back to our safe and beautiful islands.
"Overall, despite all these challenges, we expect a positive year for the Guernsey travel market.”

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